G.E. LUCALUX PSL 400Which lamp is best for your growing needs?METAL HALIDE LAMPS - This type of light is blue-orientated in the spectrum. It is the best type of light to be used as a primary light source (if no or little natural sunlight is available). This type of lamp promotes plant growth.HIGH PRESSURE SODIUM LAMPS - These lamps are red/orange in the spectrum. They are the best lamps available for ... — Ships from Vancouver, WA and/or SS: Ontario, CA, Samoa, CA, Livermore, CA, Denver, CO, Detriot, MI, Nashville, TN, York, PA, Pompano Beach, FL USA....more info.